As johnr_r says don't just change one fork they need to be replaced as a pair. I'm not certain what osha regs say in the states but Loler regs in the jk say they need to be a matched pair. Each for should have a number that matches to show they are matched. A hole in the fork means the fork is scrap the truck should be used until it's been replaced it's certainly against Loler regs in the uk